OPWDD Guidance: Eligibility Guidelines Page 6 of 27
and clinical practice guidelines established for their profession. Practitioners are trained
to appraise information obtained using psychometric and other measures. They are
expected to be cognizant of such considerations as:
• The standard error of measurement and standard error of the mean; and
• Factors that increase or decrease the validity and reliability of test and assessment
results; and
• The importance of integrating and interpreting test results in the context of
previously obtained results, clinical history, and collateral information.
These factors must be considered when deciding whether eligibility criteria for intellectual
or adaptive behavioral functioning are met.
Qualified practitioners trained and experienced in sub-specialty areas, and whose scope
of practice includes formulating a diagnostic impression, are encouraged to perform or
coordinate differential diagnostic assessments (i.e., differentiating one disorder from
another that may have some similar presenting characteristics), rather than exclusively
ruling in or ruling out single specific conditions. Such assessments may include testing
limits, identifying and evaluating significant or characteristic discrepancies between skill
and performance measures, and utilizing multiple clinical and testing measures to
evaluate the presence of a concurrent or pre-existing disorder.
Reports prepared by Master’s-level unlicensed or uncertified examiners who are qualified
practitioners, which include diagnostic statements, must be supervised and co-signed by
a licensed practitioner qualified to assess and diagnose the relevant condition, and who
has been involved in the assessment process. All practitioners may only perform work that
is within their scope of practice and based upon their education and training.
In cases where no information is available regarding age of onset of disability during the
developmental period (e.g., for someone now in mid-adulthood), DDRFOs are advised to
rely on the informed clinical judgment of appropriately licensed professionals. These
judgments should be based on the best available and obtainable information.
Efforts must be made to obtain historical records (such as school, medical, psychiatric,
mental health/psychological, or other disability records), as opposed to presuming that
such records no longer exist. DDRFOs may require documentation of efforts to obtain
records. In cases where records cannot be obtained, other sources of information (such
as retrospective as well as current collateral information from relatives, friends, neighbors,
etc.) should be considered. In addition, the nature of the person’s disability, social history,
culture, background, and primary or preferred language should be considered when
determining whether the person meets the eligibility criteria.
E. Need to Use Prevailing Diagnostic Nomenclatures and Accepted Diagnostic
Practices
It is expected that practitioners will designate diagnostic classifications that
correspond to the prevailing clinical nomenclatures at the time of the assessment
(e.g., the current edition of the International Statistical Classification of Diseases
established by the World Health Organization [ICD, WHO]; the current edition of the
Diagnostic and Statistical Manual of Mental Disorders [DSM, American Psychiatric